1. Field of the Invention
This invention relates to collets for vertical milling machines, more particularly, an improved R-8 tool-holding collet arrangement to permit those vertical milling machines to be utilized more efficiently.
2. Prior Art
This Application is a continuation-in-part application of my earlier co-pending U.S. patent application Ser. No. 09/134,878 filed Aug. 15, 1998. That Application and my earlier issued U.S. Pat. No. 5,85,039 are each incorporated herein by reference in their entirety. That Application and my '039 U.S. patent relates to improvements to vertical milling machines which milling machines have been around for many years. One very common milling machine is the Bridgeport type, universal, standard vertical milling machine. The Bridgeport milling machine may be characterized by a vertical spindle, which is manually activated by a pull handle, to move a tool towards and push it away from the surface of an article to be worked. An "R-8" collet is the specific collet utilized to hold a specific tool in the lower end of the tool spindle of the Bridgeport type machine. A tool is inserted in the R-8 collet and the "Z" axis is set, and the tool is ready to work on a workpiece. When a new tool is needed, the R-8 collet is removed from the spindle, and the tool is removed from the R-8 collet, and the new tool inserted in its place. The R-8 collet is reinserted in the spindle, the "Z" axis is re-measured, and the new tool is applied to the workpiece. The original tool may need to be re-used, so that the process is again repeated by reinserting the tool in the R-8 collet and the "Z" axis again re-measured. The R-8 collet is needed because it provides a machined surface so as to accurately mate with the spindle, thereby maintaining accuracy of the tool during it's milling operation. This type of collet is known under its common name as an "R-8" collet, specifically as defined by ANSI specification, the R-8 being critical to this invention.
It is an object of the present invention to provide an improved R-8 collet.
It is a further object of the present invention to provide an R-8 collet for a Bridgeport type universal milling machine, wherein a succession of different tools may be more easily utilized more than once by that particular Bridgeport type universal milling machine.